Crown block cable guard



V. W ZlLEN. CROWN BLOCK CABLE GUARD.

APPLICATION FILED SEPT. 13. 1921.

Patented. July 25, 1922.,

m wm

units] stares VICTOR W. ZILEN, OF CHATIANOQGA, TENIIESSEE, ASSIGZLQ-t;TO LUCEY llIAN'UIEAo- TUBING CORPORATION, OE GHATTAIIQOGA,

TENNESSEE.

.iaeassc.

To all whom it may concern.

Be it known that I l iciror. IV. Zruinin a citizen of the United States.lESlCllllg at had to the accompanying drawings,

forming part of this specification.

This invention relates to crown blocks of drilling rigs and isespecially applicable to guards adapted for use in connection with thesheaves or pulleys carried on the crown block; i

As is well known, very heavy loads are suspended from the sheaves on thecrown block of well drilling rigs and under certain conditions such, forinstance, as a sudden variation of the load from maximum to zero, thecable by which the load is sus pended from the sheaves will jump out ofthe grooves in the sheaves. An object of the present invention isto meetthis condi tion and insure the safety of the operator by providing thecrown block with ruards for each of the sheaves that will effectuallyprevent the displacement of the cable from the sheaves.

In the accompanying drawings.

Figured is a top plan view of a crown block embodyingthe presentimprovements,

all except one or two of the guards being shown partly in section;

Fig.2 is a side elevation. partly in. sectiomof the crown block andcable guards; and

Fig. 8 is a sectional view on the line 33, Fig. I

Practically all crown blocks now in use consist generally of pluralit ofspaced frame members having the various sheaves or pulleys, such as thedrilling line, sand line and casing; line sheaves. mounted thereonbetween the frame members and while the present invention is applicableto any form of crown'blockja block and pullevs such asthose described inU. S. Patent'No.

1,368,775, dated February 15, 1921. have been selected for purposes ofillustration in the present case and a brief description of theessential parts thereof will suflice.

The crown block consists of five frame members 10 preferably formed ofmetal I- Specification of Letters Patent.

TNESSEE, it CORPOEATIGN O33 CROWN BLO JI'I CABLE GUARD.

beams, two of said frame members being somewhat longer than, andextending at one end beyond. the others to receive the sand line sheave11. Frame members 10 are spaced apart from each other by spacer frames il, preferably of the type described in the above mentioned patent. andsaid frame members are provided on the upper surfaces with suitablebearings for the shafts 15 of the sand line sheave 11, the casing;sheaves l2 and the drilling line sheave 13, each of said sheaves beingpositioned on'its respective shaft in the spaces intermediate adjacentmembers 10 of the block. Further detailed description of thettrame'members of the crown block, or of the sheaves and shafts, is deemedunnecessary here for an understanding of this invention. although a fulldisclosure and description of these parts will be found in the patentbefore referred to. I T

In oil well rigging a cable fronra hoisting apparatus is passed over thesheaves of the cr wn block and under sheaves of a vertically travelingblock (not shown) below from a hoisting hook on the traveling block, theload being transmitted from thetrarelingbloclr to the crown block by thecables and from the crown block. which is on the top of the derrick, tothe frame members of the derrick. Normally. the crown block is subjectedto substantially vertical strains only, but under various operatingconditions. such a sudden ariation of the load, the elasticity of thederrick. the crown block framing: and the cable distorts the verticaltransmission ofstrains to such a degree as to cause the cable to jumpout of the groove in the crown block sheaves. To prevent this accidentaldisplacement of the cables, due to this and other causes, cable guardsare provided on the crown block for each of the sheaves.

In the preferred embodiment of the invention the uards 16 arecomparatively narrow. being: a title wider than the sheaves, and are ofarcuate formation, conforming to the contour of that portion of thesheaves above the frame members 10. Two guards are provided for eachsheave, one on each side of the sheave, practically the entire peripheryof the sheave above the frame members being enclosed by the two guards.Each guard is provided with a base 17 extending laterally on each sideof the guard and of sufficient length to straddle or bridge the spacebetween two adjacent frame members 10, the opposite ends of base 17resting on the top of the frame members with the guard 16 positionedintermediate the frame members and in proximity to the grooved peripheryof the sheave.

For securing the guard on the crown block a clamping plate 18 ofsutlicient length to bridge the space between the frame mem bers ispositioned beneath the guard base 17 in engagement with the bottomsurfaces of the flanges to the I-beams. A pair of bolts 19 extendthrough the plate and guard base with the heads of the bolts seated inrecesses 20 in the plate 18'to prevent rotation of the bolts. and theplate and guard are secured or clamped on the crown block frame membersby nuts threaded on the upper ends of bolts 19, the bolts beingpreferably arranged with their threaded ends projecting above the crownblock to render them accessible.

As will be obvious the guards can be adjusted towards and away from asheave, that is, longitudinally of the frame members 10,by loosening thebolts 19 and to permit adjustment of the guard transversely of themembers 10 and a sheave, the guard base 17 is provided on opposite sidesof the guard with elongated slots 21. The bolts 19 extend through saidslots and by loosening the bolts the guard can be adjusted transversely,the base 17 being made sufliciently long to maintain its bearing on bothof the frame members 10 in any of the locations to which it might bemoved.

Furthermore, by mounting the guards on the frame members instead of onthe sheaves or on the shafts of the sheaves the guards can easily beremoved without disturbing the sheaves. This is very advantageous particularly when there is a load imposed on the sheave, because under theseconditions it would be rather troublesome to remove the sheave or sheaveshaft if the guard was mounted on either of these members instead of onthe frame.

What is claimed is:

1. In a crown block, the combination of spaced frame members, sheavesjournaled on the frame members and positioned in said spaces. guards foreach of said sheaves,

' said guards being movable toward and away from their respectivesheaves to vary the distance between the sheaves and their respectiveguards.

2. In a crown block, the combination of spaced frame members, sheavesjournaled on the frame members and positioned in said spaces, and guardsfor each of said sheaves, said guards being adjustably mounted on theframe members and said guards being removable from said frameindependently of the sheaves and sheave mountings.

3. In a crown block, the combination of.

spaced frame members, sheaves journaled on the frame members andpositioned in said spaces, guards for each of said sheaves, said guardsbeing movable towards and away from the sheaves and transversely of thesheaves, and means for locking said guards in adjusted position.

4-. In a crown block, the combination of spaced frame members havinglateral flanges, sheaves ournaled on said members and positioned in saidspaces, guards for each of said sheaves, each of said guardshavinga baseadapted to bridge the space between adjacent frame members and rest onthe upper surfaces of the flanges of said members, a clamping plate foreach guard adapted to bridge the space between adjacent frame membersand seat against the under surfaces of said flanges, and securing meansextending through said plate and guard base.

5. In a crown block, the combination of spaced frame members havinglateral flanges, sheaves journalled on said members and positioned insaid spaces, guards for each of said sheaves, each of said guards havinga slotted base adapted to bridge the spaces be tween adjacent framemembers and rest on the flanges of said' members, a clamping plate foreach guard adapted to. seat against the bottom surface of said flangesbelow the guard base, and releasable locking elements extending throughsaid plates and slotsin the base of each guard.

6. A rope guard for crown block sheaves comprising a baseextending onopposite sides of the guard, there being an elongated slot in the baseon each side of saidguard, a clamping plate, and securing elementsextending through the plate and the slots in the guard base.

7. In acrown block, the combination of the sheave support, a sheaveguard, a guard base extending on opposite sides of the guard and adaptedto engage the sheave support, there being an elongated slot in the baseon each side of the guard. a clamping plate adapted to engage the sheavesupport beneath the guard base, and means extending through the plateand the slots in the base for securing the guard on the sheave support.

. VICTOR W. ZILEV.

